1. Field of the Invention
The present invention relates to a semiconductor wafer transfer apparatus, and more particularly, to a semiconductor wafer transfer apparatus having a wafer supporting block which supports a semiconductor wafer.
2. Description of the Related Art
Generally, a semiconductor wafer is processed into a semiconductor device through various operations, and a transfer apparatus is needed to transfer the semiconductor wafer from one process operation to another process operation.
During these process operations, it is desirable to prevent the semiconductor wafer from being contaminated by dust and particles.
FIGS. 1 and 2 show a conventional semiconductor wafer transfer apparatus 101 which includes a wafer supporting block 120 that supports a semiconductor wafer (not shown), and a casing 110 that is formed along a moving path of the wafer supporting block 120. A guiding slot 113 is provided to the casing 110 so as to allow a part of the wafer supporting block 120 to pass therethrough. The semiconductor wafer transfer apparatus 101 further includes a driving part 130 which is accommodated in the casing 110 and moves the wafer supporting block 120, a connection part 140 which connects the driving part 130 with the wafer supporting block 120, and a guide unit 150 which is combined to both the wafer supporting block 120 and the connection part 140 inside the casing 110, and guides the wafer supporting block 120.
The wafer supporting block 120 includes a wafer supporter 123 which is provided outside the casing 110 and mounted with a hand (not shown) which holds the semiconductor wafer, and a combination part 125 which is extended from the wafer supporter 123 and combined to both the connection part 140 and the guide unit 150 with screws 159 that pass through the guiding slot 113.
The casing 110 surrounds the driving part 130, the guide unit 150 and the connection part 140, and partitions them off from a wafer transfer chamber (not shown), a wafer reaction chamber (not shown), etc., so as to prevent the semiconductor wafer from being contaminated by dust and particles generated from, for example, the driving part 130. The combination part 125 of the wafer supporting block 120, which is driven by the driving part 130, passes and is guided along the guiding slot 113. The casing 110 further includes a casing cover 115.
The driving part 130 includes a belt 133 which is connected to the connection part 140 and moves together with the connection part 140, a plurality of pulleys 135 which engage with the belt 133, and a driving motor 137 which drives a corresponding one of the pulleys 135. The driving part 130 is supported by a driving part supporter 139, which is attached to a floor of the casing 110.
The belt 133 is fastened to a belt connection part 143 of the connection part 140 with bolts 148 and nuts 149, and moves the wafer supporting block 120 connected to the other part of the connection part 140 where the driving motor 137 is operated.
The pulleys 135 are placed at opposite ends of the belt 133, and are used to transmit a rotary motion from the driving motor 137 to the belt 133.
The connection part 140 includes the belt combining part 143 which is combined to the belt 133 with the bolts 148 and nuts 149, and a guide combining part 145 which is combined to the combination part 125 of the wafer supporting block 120 and the guide unit 150 with the screws 159.
The guide unit 150 is provided inside the casing 110, and includes a guide member 153 which is combined to the combination part 125 of the wafer supporting block 120 and the guide combining part 145 of the connection part 140, and a guide rail 155 which is attached to the floor of the casing 110 and guides the guide member 153.
The guide member 153 has a rectangular block shape and is guided by the guide rail 155. The guide rail 155 has an “U”-shape which accommodates the guide member 153, and is arranged along a moving path of the guide member 153.
The conventional semiconductor wafer transfer apparatus 101 is operated as follows.
Where the driving motor 137 rotates the pulley 135, the belt 133 runs on the pulleys 135 so as to move the connection part 140. Accordingly, the wafer supporting block 120, which is combined with the connection part 140, is guided by the guide unit 150 and moves to transfer the semiconductor wafer. Where the driving motor 137 reverses the rotation of the pulley 135, the wafer supporting block 120 is returned to an original position. That is, as the driving motor 137 alternates the rotating directions, the wafer supporting block 120 reciprocates within a predetermined distance, thereby repeatedly transferring the semiconductor wafer.
However, in the conventional semiconductor wafer transfer apparatus 101, the semiconductor wafer can be contaminated by dust and particles which are generated from an operation of the driving part 130 and introduced to the semiconductor wafer through the guide slot 113.